Traditional methods of producing beams of velocity selected neutral atomic or molecular species do not work well throughout the 1 to 20 eV kinetic energy range, for which atomic velocities can exceed one million cm/sec. Standard mechanical velocity selection techniques are limited to maximum transmitted velocities of about 100,000 cm/sec, or they require very long atomic flight distances of about 100 cm. Beams of nearly monoenergetic very fast neutral species can be produced routinely by charge exchange neutralization of a beam of suitable parent ions. However, this technique fails for kinetic energies below about 10 eV due to space charge limitations on the intensity of the parent ion beam.
The laser ablation into vacuum process provides a compact source of intense beams of neutral and ionic species throughout the desired kinetic energy range, but with very broad kinetic energy distributions.